railway

摘要： Railway switches and crossings constitute a small fraction of linear track length but consume a large proportion of the railway track system maintenance budget.While switch and crossing(S&C)faults rarely prevent trains from running,switches and crossings are the source of many faults and need continual attention.On the rare occasions when trains are prevented from running the cost of the disruption is very high.Condition monitoring of the point operating equipment that moves the switchblades has been in use for many years but condition monitoring of the state of the switch in terms of the support and mechanical damage as trains pass over has only recently started to become possible.To this end,it is important to understand the correlation between S&C faults and sensor data that can detect those faults.This paper assesses some of the data collected from multiple sensors variously positioned on and around a switch and crossing on the UK mainline for a few days of normal train operation.Accelerometers,geophones,and strain gauges were installed at the locations where they were anticipated to be most useful.Forces at the load transfer point on the crossing nose were estimated from two separate strain gauge bridges and possible use of acceleration on the crossing is discussed.Correlations between different data are analysed and assessed and correlation between peak estimated load transfer forces and accelerations is presented.Based on the analysis,conclusions are drawn about the different types of dynamic information around S&Cs that can be obtained from a variety of sensor types.

摘要： Sand barriers are the most widely used mechanical implements for wind-blown sand control and desertification prevention.However,there is no standard quantitative cost analysis of the sizes and materials required for sand barriers.In this study,based on the original land grid division model for optimal resource utilization,we calculated the total side lengths of square and regular hexagonal sand barriers with the sizes of 1.0 m×1.0 m,2.0 m×2.0 m,and 3.0 m×3.0 m in a desertified region of the Shapotou area on the southeastern edge of the Tengger Desert,China.Then,through literature review and social survey,we obtained the material cost and material utilization amount of sand barriers with different materials and sizes.Finally,we calculated the costs of square and regular hexagonal sand barriers comprised of wheat straw,corn stalk,Salix mongolica,poly lactic acid,magnesium cement,and high-density polyethylene,with the sizes of 1.0 m×1.0 m,2.0 m×2.0 m,and 3.0 m×3.0 m.The results show that the material cost of regular hexagonal corn stalk sand barriers with the size of 3.0 m×3.0 m is the lowest,while the material cost of square magnesium cement sand barriers with the size of 1.0 m×1.0 m is the highest.When using the same material,the cost of regular hexagonal sand barriers is lower than that of square sand barriers with the same size.When using the same size,the cost of sand barriers with corn stalk material is lower than that of sand barriers with other materials.Based on the above analysis,we can conclude that the economic benefits of regular hexagonal sand barriers are greater than those of square sand barriers.This study provides a theoretical basis for accurately calculating the material cost of sand barriers,particularly for the estimated cost of mechanized sand barrier engineering projects.

摘要： Purpose–This study aims to research the development trend,research status,research results and existing problems of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.Design/methodology/approach–Based on the investigation and analysis of the development history,structure form,structural parameters,stress characteristics,shear connector stress state,force transmission mechanism,and fatigue performance,aiming at the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge,the development trend,research status,research results and existing problems are expounded.Findings–The shear-compression composite joint has become the main form in practice,featuring shortened length and simplified structure.The length of composite joints between 1.5 and 3.0 m has no significant effect on the stress and force transmission laws of the main girder.The reasonable thickness of the bearing plate is 40–70 mm.The calculation theory and simplified calculation formula of the overall bearing capacity,the nonuniformity and distribution laws of the shear connector,the force transferring ratio of steel and concrete components,the fatigue failure mechanism and structural parameters effects are the focus of the research study.Originality/value–This study puts forward some suggestions and prospects for the structural design and theoretical research of the steel–concrete composite joint of railway long-span hybrid girder cable-stayed bridge.

摘要： SUMMARIES OF TOP NEWS STORIES CHINA 358 km of New High-Speed Rail Introduced in First Four Months China put 581 km of new railway lines into service in the first four months of the year,including 358 km of high-speed railway。

摘要： Urban railway systems differ greatly from general power systems in that they use direct current(DC)power supply and that the location and power requirements of the loads change.The position and power consumption of the load shall be interpreted continuously every second,or in a fixed unit of time,for a specific period of time during which the operating conditions are repeated.The additional analysis of energy-saving systems being considered as energy efficiency improvement methods requires more complex load flow analysis algorithms.Simulations are performed load flow every time step.The power of an electric railway power feeding system is the power consumed or produced by a train.Because the amount and position of the load change rapidly over time,load flow analysis continues over time.Therefore,based on the method of obtaining solutions by constructing node equations for load flow analysis in this study,load flow analysis was performed through algorithms with energy-saving systems applied.Both thetrain performance simulation(TPS)and power simulation results show that the actual measurement data are estimated almost equally.

摘要： Scene 1 The paper-chase游戏"The boys from the school in Maidbridge are having a paper-chase today,"said Bobbie,the next morning."Perks thinks they’ll go along beside the railway line.We could go and watch."

摘要： In this paper,a new type of automatic transmitter(AT)is proposed to properly adjust the voltage of the train without installing additional equipment.The proposed tap-changing AT is expected to raise the voltage between catenary and rail by regulating the turn-ratio between primary and secondary winding according to catenary voltage and verified its effects through the multi ports network analysis technique modeling of it.Through the simulation and analysis of the electric railway systems,it is shown that it can secure the load capacity and solve the large voltage drop problem by raising the voltage across railway vehicles back to the normal voltage level.

摘要： On December 2,Song Chao’s excitement for the opening of the China-Laos Railway peaked.Despite his Chinese name,Song is Laotian.He works as an interpreter for the railway project and has been studying China’s railway engineering technology during his spare time.Song considers the project team like a family.“Everyone,Lao and Chinese alike,has been working conscientiously,”he said.

摘要： 1.Introduction The Beijing–Zhangjiakou high-speed railway(HSR)is an important transport facility that will serve the Beijing 2022 Olympic Winter Games.Its main line is 174 km long,and its maximum design speed is 350 km·h^(-1).It is the world’s first HSR to be designed based on the concept of an intelligent railway.Construction of the Beijing-Zhangjiakou HSR began on 29 April 2016,and the line was put into operation on 30 December 2019.

摘要： The China-Laos Railway has become a major pillar of Laos’dream to transform from a landlocked country into a land-linked hub.Thanks to perseverance and dedication from railway designers and workers,this dream is coming true.Trailblazers Chen Jianguo of China Railway Eryuan Engineering Group Co.Ltd.is executive deputy manager of the Boten-Vientiane section of the China-Laos Railway.

摘要： In order to adapt to the new requests of the high-speed railway，thisDaper presents a microwave communication system between trains and ground tacilities．Concretely，the paper analyses propagation characteristics of the wirelesscommunication system，and compares several microwaves in different trequencybands．Secondly，factors which affect the Bit Error Rate at the receive antennaare discussed in detail，such as the velocity of the train and rainfall．Computersimulation indicates that the propagation characteristics can satisfied the requestsof the special communication．